Add Flow type for ActivityIndicator

Summary: Changelog: [Internal] - Add a type definition for ActivityIndicator

Reviewed By: NickGerleman

Differential Revision: D38850509

fbshipit-source-id: c3ca50be8fbcec0f0f43b036f8768f4462fa4991

Libraries/Components/ActivityIndicator/ActivityIndicator.flow.js

@@ -0,0 +1,57 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @format
+ * @flow
+ */
+
+'use strict';
+import * as React from 'react';
+import {type ColorValue} from '../../StyleSheet/StyleSheet';
+import type {HostComponent} from '../../Renderer/shims/ReactNativeTypes';
+import type {ViewProps} from '../View/ViewPropTypes';
+
+type IndicatorSize = number | 'small' | 'large';
+
+type IOSProps = $ReadOnly<{|
+  /**
+    Whether the indicator should hide when not animating.
+
+    @platform ios
+  */
+  hidesWhenStopped?: ?boolean,
+|}>;
+
+type Props = $ReadOnly<{|
+  ...ViewProps,
+  ...IOSProps,
+
+  /**
+   	Whether to show the indicator (`true`) or hide it (`false`).
+   */
+  animating?: ?boolean,
+
+  /**
+    The foreground color of the spinner.
+
+    @default {@platform android} `null` (system accent default color)
+    @default {@platform ios} '#999999'
+  */
+  color?: ?ColorValue,
+
+  /**
+    Size of the indicator.
+
+    @type enum(`'small'`, `'large'`)
+    @type {@platform android} number
+  */
+  size?: ?IndicatorSize,
+|}>;
+
+export type ActivityIndicator = React.AbstractComponent<
+  Props,
+  HostComponent<mixed>,
+>;

Libraries/Components/ActivityIndicator/ActivityIndicator.js

@@ -14,8 +14,8 @@ import * as React from 'react';
 import Platform from '../../Utilities/Platform';
 import StyleSheet, {type ColorValue} from '../../StyleSheet/StyleSheet';
 import View from '../View/View';
-import type {HostComponent} from '../../Renderer/shims/ReactNativeTypes';
 import type {ViewProps} from '../View/ViewPropTypes';
+import type {ActivityIndicator as ActivityIndicatorType} from './ActivityIndicator.flow';
 
 const PlatformActivityIndicator =
   Platform.OS === 'android'
@@ -183,10 +183,8 @@ const ActivityIndicator = (
   ```
 */
 
-const ActivityIndicatorWithRef: React.AbstractComponent<
-  Props,
-  HostComponent<mixed>,
-> = React.forwardRef(ActivityIndicator);
+const ActivityIndicatorWithRef: ActivityIndicatorType =
+  React.forwardRef(ActivityIndicator);
 ActivityIndicatorWithRef.displayName = 'ActivityIndicator';
 
 const styles = StyleSheet.create({